MONDAY, Nov. 12 (HealthDay News) -- People with liver cancer tied to infection with the hepatitis B virus who got antiviral therapy after cancer surgery had a lower risk of tumor recurrence than those who did not get it, according to a new study.

"Hepatitis B infection commonly leads to the development of liver cancer in patients with and without cirrhosis," explained one expert not connected to the study, Dr. David Bernstein, chief of the division of hepatology at North Shore University Hospital in Manhasset, N.Y.

He also noted that antiviral therapy is now standard practice for these patients. Most experts "agree that all patients with hepatitis B and liver cancer, whether cirrhosis is present or not, and any level of the hepatitis B virus in the blood should be treated with antiviral therapy," Bernstein said.

In the new study, Taiwanese researchers compared results for more than 4,500 patients who had surgery for hepatitis B virus-related liver cancer between 2003 and 2010. The treated group consisted of about 500 patients who received antiviral therapy (drugs called nucleoside analogues) after surgery, while the remainder received no antiviral therapy.

The treated group had half the rate of cancer recurrence compared to the untreated group (21 percent vs. 44 percent) and a lower death rate (11 percent vs. 28 percent), according to the team led by Dr. Chun-Ying Wu, of National Yang-Ming University in Taipei.

Over six years, the risk of liver cancer recurrence was 46 percent in the treated group and 55 percent in the untreated group, while the risk of death was 29 percent in the treated group and more than 42 percent in the untreated group.

The researchers calculated that antiviral therapy reduced the risk of cancer recurrence by a third overall. The use of cholesterol-lowering statin drugs also was associated with about a third less risk, and the use of painkillers such as aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with a 20 percent reduced risk.

The study, published online Nov. 12 in the Journal of the American Medical Association, also was scheduled for presentation Monday at the annual meeting of the American Association for the Study of Liver Diseases, in Boston.

Bernstein cautioned that, in his opinion, the study had some flaws.

"The most important is the lack of data regarding the hepatitis B viral load in both the treated and untreated patient groups," he said. He said information on viral load is important, since "there may be a subset of patients with cirrhosis and no detectable hepatitis B virus in the blood who develop liver cancer, [and] it is difficult to recommend hepatitis B treatment in this group."

"The second major flaw is the short duration of follow-up," Bernstein said.

Still, he said, the "take-home message" from the study supports the "current standard of care, which is that all patients with liver cancer secondary to hepatitis B and detectable hepatitis B virus should be treated with oral antiviral therapy, as these therapies are safe, effective and have minimal side effects."

Another expert agreed.

"This new information is extremely valuable," said Dr. Peter Malet, director of the Center for Liver Diseases at Winthrop-University Hospital in Mineola, N.Y.

"Treatment of chronic hepatitis B with an oral medication is actually standard of care now," Malet noted, and "the available medications are taken once a day, are safe and have minimal side effects."

He said that, in most cases, insurance should cover the cost of antiviral medications. But he also stressed that most cases of primary liver cancers are not triggered by hepatitis B infection, and few liver tumors are amenable to surgery.

"The actual number of patients in the United States to whom this approach applies is rather small," he said.